But could we just back up slightly -- why do you want to do this?

I was mainly wanting to attempt this to have a look at (for curiosity's sake) how different applications are communicating with the OS. I also wanted to see how these applications reacted to being given unexpected (tamped with) values from the OS.
Will Detours Express 3.0 facilitate for this?

I also thought it may be a fun programming endeavour.

I mealy wanted to block network access for the sake of avoiding confusion regarding whether the application was receiving data from the OS, or from the internet. But it's not too important, I can just use a firewall, or pull out the ethernet cord.
I just like my solutions to be a bit more (read as "

unnecessarily"

) elegant, haha

But yes. Will Detours Express 3.0 facilitate my curiosity driven needs?